The work proposed involves the application of mass spectrometry to several problems in pharmacology and toxicology. Specifically, we propose to characterize products of the alkylation of deoxyguanosine by chloroethyl ethyl sulfide, to improve and exploit our new technique for synthesis of glucuronides, to characterize a number of synthetic glucuronides by gas chromatography and mass spectrometry, to determine pharmacokinetic curves for cyclophosphamide and two of its metabolites, to study scrambling of the ionizing proton in chemical ionization of cyclohexanol and to characterize a novel conjugate of bilirubin excreted in the absence of UDP-glucuronyl transferase. BIBLIOGRAPHIC REFERENCES: Fenselau, C., S. Kelly, M. Salmon and S. Billets. The Absence of Tetrahydrocannabinol in Hops. Food and Cosmetic Toxicology 14, 1975. Parikh, I., D. W. MacGlashan and C. Fenselau. Immobilized Glucuronyl Transferase for the Synthesis of Conjugates. J. Med. Chem. 19, 296-299, 1976.